This invention relates to polyester fiber treatment agent compositions, and more particularly to a polyester fiber treatment agent composition that provides polyester fiber with properties such as smoothness, rebound, compression recovery, and fatigue resistance.
Polyester fiber has a higher compression modulus and a better compression recovery than nylon, acrylic, polyvinyl chloride, and polypropylene fibers. These advantages make polyester fiber well-suited for use as staple fiber for padding, wadding, or filling used in futons, comforters, quilts, pillows, cushions, and stuffed toys, and polyester fiber has become widely employed in these applications. It is known to treat polyester fiber with compositions containing organoalkoxysilanes, e.g., aminoflnctional alkoxysilanes or epoxyfunctional alkoxysilanes, to impart a feather-like or fur-like handle to the fiber, Japanese Application Sho 49-133698; Sho 50-48293; Sho 58-214585; and Sho 62-41379. This treatment provides the fiber with properties such as softness, flexibility, smoothness, rebound, and compression recovery. At the same time, the alcohol produced from the alkoxysilane can contaminate the working environment and can create a fire risk.
Polyester fiber can also be treated with a mixture of aminofunctional polysiloxane and epoxyfinctional polysiloxane, Japanese Application Sho 48-17514; and Japanese, Application Hei 5-59673. This method, however, requires a high temperature thermal treatment to produce its intended effects, and the use of heat can cause deterioration of the polyester fiber.
Therefore, the object of the invention is to provide a polyester fiber treatment agent composition that can impart a very good handle to polyester fiber, particularly to polyester fiber wadding, padding, or fill.
These and other features and objects of the invention will become apparent from a consideration of the detailed description.
The invention relates to a polyester fiber treatment agent composition that is a water-based emulsion comprising
(A) an aminofunctional organopolysiloxane with the general formula 
xe2x80x83in which R denotes a C1 to C20 substituted or unsubstituted monovalent hydrocarbon group, R1 denotes a C1 to C10 divalent hydrocarbon group, R2 and R3 are each selected from the group consisting of a hydrogen atom and a C1 to C20 substituted or unsubstituted monovalent hydrocarbon group, A denotes a C1 to C20 alkyl group, m and n are each integers with a value of at least 1, and a is 0-5,
(B) an aminofunctional organopolysiloxane with the general formula 
xe2x80x83in which R denotes a C1 to C20 substituted or unsubstituted monovalent hydrocarbon group, R1 denotes a C1 to C10 divalent hydrocarbon group, R2 and R3 are each selected from the group consisting of a hydrogen atom and a C1 to C20 substituted or unsubstituted monovalent hydrocarbon group, x and y are each integers with a value of at least 1, and a is0-5,
where the ratio of component (A):component (B) is from 1:0.1 to 1:10 on a weight basis, (C) a nonionic surfactant, and (D) water.
The aminofunctional organopolysiloxane (A) used in the composition is the essential component for conferring durability and rebound to polyester fiber. This organopolysiloxane (A) undergoes an increase in its molecular weight due to the condensation reaction of its terminal alkoxy groups. The larger molecular weight enables it to become intertwined with and anchored to the polyester fiber, resulting in the improvement in durability and rebound. Component (A) has the following general formula. 
R in the formula denotes a C1 to C20 substituted or unsubstituted hydrocarbon group and can is exemplified by saturated aliphatic hydrocarbon groups such as methyl, ethyl, propyl, butyl, octyl, decyl, dodecyl, and tetradecyl; unsaturated aliphatic hydrocarbon groups such as vinyl and allyl; saturated alicyclic hydrocarbon groups such as cyclopentyl and cyclohexyl; aromatic hydrocarbon groups such as phenyl, tolyl, and naphthyl; and groups afforded by replacing part of the hydrogen atoms in any of the preceding groups with halogen or epoxyfunctional organic groups. The R groups in the formula may all be the same or may be different, but R is preferably methyl.
R1 for component (A) denotes a C1 to C10 divalent hydrocarbon group. R1 can be exemplified by alkylene groups such as ethylene, propylene, and butylenes; and by arylene groups such as phenylene, but it is preferably ethylene or propylene.
R2 and R3 are each a hydrogen atom or a C1 to C20 substituted or unsubstituted monovalent hydrocarbon group. Monovalent hydrocarbon groups encompassed by R2 and R3 can be exemplified by the same groups as R. R2 and R3 can be the same or they may differ.
A in the formula for (A) denotes a C1 to C20 alkyl group such as methyl, ethyl, propyl, butyl, octyl, decyl, dodecyl, and tetradecyl.
The subscripts m and n are each integers with a value of at least 1. While the upper limit on these subscripts is not critical, in order to impart softness, flexibility, smoothness, and compression recovery, the subscripts preferably have a value to provide a kinematic viscosity at 25xc2x0 C. for the organopolysiloxane of at least 50 mm2/s, and more preferably in the range of 300 to 30,000 mm2/s. Subscript a is an integer with a value of 0-5, but it will generally be 0 or 1.
The siloxane unit bonding in the formula for component (A) can be random or block. One method for synthesizing aminoflmctional organopolysiloxane (A) is reaction of a diorganopolysiloxane or diorganosilane with the general formula 
in which R is the same as defined above, and p is an integer with a value of at least 1; and an organoalkoxysilane with the general formula 
in which R, R1, R2, R3, A, and a, are the same as defined above.
The diorganopolysiloxane used in this synthesis can be exemplified by an hydroxyl-endblocked dimethylpolysiloxane having a kinematic viscosity at 25xc2x0 C. of 10-30,000 mm2/s. The organoalkoxysilane used in this synthesis can be exemplified by the composition N-xcex2-(aminoethyl)-xcex3-aminopropylmethyldimethoxysilane. The diorganopolysiloxane and the organoalkoxysilane can be reacted with each other with heating, or with heating in the presence of a basic catalyst followed by neutralization of the basic catalyst with an acid. The basic catalyst can be exemplified by potassium hydroxide, sodium hydroxide, or lithium hydroxide.
The following compositions are examples of aminofunctional organopolysiloxane (A). 
Aminofunctional organopolysiloxane (B) is the essential component for conferring an excellent smoothness, flexibility, and softness to the polyester fiber. An additional and significant improvement in the rebound characteristics can be induced by reaction of a portion of hydroxyl in organopolysiloxane (B) and alkoxy in component (A).
Component (B) is defined by the general formula 
in which R, R1, R2, R3, and a, are the same as defined above. Subscripts x and y are each integers with a value of at least 1. While the upper limits on the value of these subscripts is not critical, in order to impart softness, flexibility, smoothness, and compression recovery, it should have a value to provide a kinematic viscosity at 25xc2x0 C. for the organopolysiloxane of at least 50 mm2/s, more preferably in the range from 300-30,000 mm2/s. The siloxane unit bonding for component (B) can be random or block.
One method for synthesizing aminofunctional organopolysiloxane (B) comprises the base catalyzed reaction of a diorganosilane or diorganosiloxane with the general formula 
in which R and p are the same as defined above, and q is an integer with a value of at least 3; with the hydrolysis and condensation product of an organoalkoxysilane with the general formula 
in which R, R1, R2, R3, A, and a, are the same as defined above.
The diorganosiloxane used in this synthesis is exemplified by hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and hydroxyl endblocked dimethylpolysiloxanes. The alkoxysilane hydrolysis and condensation product can be exemplified by silanol functional hydrolysis and condensation products afforded by hydrolysis of N-xcex2-(aminoethyl)-xcex3-aminopropylmethyldimethoxysilane in the presence of excess water. The basic catalyst can be exemplified by potassium hydroxide, sodium hydroxide, and lithium hydroxide. The reaction is generally carried out using heat. Completion of the reaction is followed by neutralization of the basic catalyst with an acid.
The following compounds are examples of aminofunctional organopolysiloxane (B). 
The benefits of this invention are achieved by using the combination of aminofunctional organopolysiloxanes (A) and (B). The use of (A) alone results in an excessive amount of condensation polymerization among polysiloxane molecules, which while leading to an improvement in rebound, also results in a lower smoothness, softness, and flexibility. The use of (B) alone can to some degree produce a good smoothness, softness, and flexibility, but it is not durable. In addition, no rebound is obtained with the use of only (B). The (A):(B) component blending ratio on a weight basis should be in the range of 1:0.1 to 1:10.
The nonionic surfactant (C) used in the composition functions to disperse components (A) and (B) in water and produces the water-based emulsion. Component (C) can be exemplified by polyoxyethylene alkyl ethers and polyoxyethylene-polyoxypropylene alkyl ethers in which the alkyl group is lauryl, cetyl, stearyl, or trimethylnonyl; polyoxyethylene alkylphenyl ethers in which the alkylphenyl group is nonylphenyl or octylphenyl; polyethylene glycol/aliphatic acid esters afforded by addition polymerization of ethylene oxide with an aliphatic acid such as stearic acid or oleic acid; polyoxyethylene glycerol aliphatic acid esters; and polyglycerol aliphatic acid esters. A single type of nonionic surfactant or combination of two or more types of nonionic surfactants can be used as component (C). Component (C) is preferably present in the composition at 3-30 weight parts for each 100 weight parts of the total of components (A) and (B).
The water (D) in the composition functions as the dispersing medium for components (A), (B), and (C). At a minimum, water should be present in sufficient quantity to enable the composition to be converted to a water-based emulsion. In preferred embodiments, water is used at 50-20,000 weight parts for each 100 weight parts of the total of components (A), (B), and (C).
The composition can be prepared by first preparing separate emulsions of components (A) and (B) using nonionic surfactant (C) and then mixing the two emulsions, or by first mixing components (A) and (B) and then emulsifying the mixture using nonionic surfactant (C). The composition can be prepared using emulsifying devices such as homomixers, homogenizers, propeller-type stirrers, line mixers, or colloid mills.
While the composition is a water-based emulsion containing components (A) through (D), it may contain other additional components such as cationic surfactants, antistatics, non-silicone organic softeners, dialkylpolysiloxanes, other organoalkoxysilanes or their partial hydrolyzates, preservatives, and antimolds. However, the dialkylpolysiloxanes should have a kinematic viscosity at 25xc2x0 C. of 50-5,000,000 mm2/s, and should not include a high degree of polymerization or organopolysiloxanes with kinematic viscosities in excess of 5,000,000 mm2/s. Should yellowing caused by the amino group in component (A) or (B) prove to be a problem, it can be ameliorated by including a compound reactive with the amino group such as an organic acid or anhydride, or an. epoxy compound.
Polyester fiber can be treated with the composition by first diluting the composition to a suitable concentration; applying it by dipping, spraying, or roll application to the polyester fiber in staple fiber, tow, yam, woven, knitted, or nonwoven form, and drying and heating at 120-180xc2x0 C. The optimal add-on of the composition with reference to polyester fiber is 0.1-3.0 weight percent as solids in the composition.